Well, I don't remember how far along the ToBEx was at the point you installed last, but it added better item and so forth handling which was causing slow down. It's "included" in the EE games...And depending on the mods you install, there's several that have had bad insight on the game mechanics. Such as one mod trying to insist setting your damage resistance bellow set number.
Good, at some point I was considering to work on a patch to optimize the HasItem trigger to solve that. Let's see how is the EE optimized
Edit: I checked the options of the Big world installer: Enhanced edition trilogy versus EE trilogy.
There are some big mods I wanted to finally go through like shadows over soubar and similar, which are not an option in EE.